Unraveling a historical mystery: Identification of a lichen dye source in a fifteenth century medieval tapestry
- Author:
- Lackner R.M., Ferron S., Boustie J., Le Devehat F., Lumbsch H.T. & Shibayama N.
- Year:
- 2024
- Journal:
- Heritage
- Pages:
- 7(5): 2370–2384
- Url:
- https://doi.org/10.3390/heritage7050112
As part of a long-term campaign to document, study, and conserve the Heroes tapestries
from The Cloisters collection at The Metropolitan Museum of Art, organic colorant analysis of
Julius Caesar (accession number 47.101.3) was performed. Analysis with liquid chromatography–
quadrupole time-of-flight mass spectrometry (LC-qToF-MS) revealed the presence of several multiply
chlorinated xanthones produced only by certain species of lichen. Various lichen dye sources have
been documented in the literature for centuries and are classified as either ammonia fermentation
method (AFM) or boiling water method (BWM) dyes based on their method of production. However,
none of these known sources produce the distinctive metabolites present in the tapestry. LC-qToF-MS
was also used to compare the chemical composition of the dyes in the tapestry with that of several
species of crustose lichen. Lichen metabolites, including thiophanic acid and arthothelin, were
definitively identified in the tapestry based on comparison with lichen xanthone standards and a
reference of Lecanora sulphurata, confirming the presence of a lichen source. This finding marks the
first time that lichen xanthones have been identified in a historic object and the first evidence that
BWM lichen dyes may have been used prior to the eighteenth century.
Keywords: lichen dye; xanthones; medieval art; textiles; LC-qToF-MS; dye analysis.
- Id:
- 36454
- Submitter:
- zpalice
- Post_time:
- Wednesday, 01 May 2024 21:08